As Structural Engineer, I am responsible for maintaining the building
structure throughout the winter. Due to the constant movement of the ice shelf
and the snow accumulation around the buildings, the legs of the building suffer
differential movements. The steelwork itself can accommodate this but the
sealed wooden superstructures in which we live and work would eventually be
damaged by support from an uneven platform. Each month throughout the winter, I
carry out a survey of the legs relative to one another and then, along with the
willing assistance from a fellow winterer, manually jack the beams to keep
within the desired tolerances. During the summer season the platforms are raised
using electric motors by around 1 m, depending on the previous year's snow
accumulation, to maintain the buildings at a height of 5 m above the snow
surface.

As the wind blows, the platforms sway. To reduce this sway to a comfortable
level, tension guys are anchored at each side of the steel frames. The tension
in these guys is monitored by strain gauges and data recorded at a computer
terminal. It is necessary to keep these guys at a desired load as vibrations
carry into the building when they are too tight and sway levels increase if they
are slack.

Snow accumulates around anything on the snow surface which is the reason for
the elevation of the buildings. Previous buildings at Halley have been built at
snow level and allowed to bury. The advantages and disadvantages of above and
below ground structures are numerous although it is certainly an advantage to
have windows in the accommodation. Although the buildings are elevated, wind
tails' still form to the up- and down-wind side of the platform which cause the
legs to try to incline. The inclinations increase over a period of years and at
a cut-off point the legs are then offset to straighten them. In order to monitor
the effects of the wind tails on the building legs, a set of glacier poles are
used as survey points to plot the profiles of the snow around the buildings with
reference to the general snow accumulation and wind speeds over time.

The ground' conditions make Halley V an extremely interesting
structure to work with, and I hope to apply engineering theory to some of the
glaciological sciences already studied around the ice shelf. The area of concern
and the time-scales relevant to each discipline differ greatly, but hopefully
the gap can be bridged with the investigation into the action of the structures
here at Halley V.